Sheet feed mechanism for printing presses



Jan. 10, 1939. w. G. HACKBARTH SHEET FEED MECHANISM FOR PRINTING PHESSE Filed Feb. 25, 1938 2 Sheets-Sheet l Jan. 10, 1939. w HACKBARTH 2,143,514

SHEET FEED MECHANISM FOR PRINTING PRESSES Filed Feb. 23, 1938 2 Sheets-Sheet 2 INVENTOR ATTORNEYS Patented Jan. 10, 1939 UNITED STATES SHEET FEED MECHANISM FOR PRINTING PRESSES Walter G. Hackbarth, Milwaukee, 'Wis., assignor to C. B. Cottrell & Sons Company, Westerly, R. I., a corporation of Delaware Application February 23, 1938, Serial No. 191,881

12 Claims.

This invention relates to sheet feed mechanism for printing presses and has for its object to provide novel and effective means for feeding sheets in register from a source of sheet supply to a high speed rotary press.

This invention comprises novel-means for driving a sheet feed rotary carrier at varying speeds during each revolution thereof to cause a stopped and registered sheet to be taken from the source of sheet supply, as, for instance, a sheet feeding means or a sheet feed table, while the carrier is traveling at a low surface speed; to then speed up the sheet and to finally reduce the speed of the sheet to cause it to be transferred to a constant speed rotary carrier, such as the impressi-on cylinder of a printing press unit, while the sheet is traveling at approximately the surface speed of said constant speed rotary carrier.

This invention more particularly comprises a novel means for controlling the varying surface speed of the sheet feed carrier, said means including a constant speed gear driven from the impression cylinder gear and loosely mounted on the feed carrier shaft or journal, and intermeshing gear segments, one carried by the constant speed feed carrier gear and the other fixedly mounted on the said feed carrier shaft; said gear segments being under the control of a stationary cam to rock the sheet feed carrier gear 30 segment for speeding up and slowing down the feed carrier at predetermined portions of each rotation thereof.

My invention further comprises a friction brake acting as a drag for the feed carrier shaft for overcoming the inertia of the feed carrier to prevents its overrunning its true position when being slowed down during its rotation.

A practical embodiment of my invention is represented in the accompanying drawings, in 40 which Fig. 1 represents a detail side elevation, partly in section, of so much of a rotary printing press as will illustrate my novel means for varying the surface speed of the sheet feed carrier during 45 one revolution thereof; the parts being in the positions they assume as the slow traveling feed carrier grippers have taken a stopped and registered sheet from a sheet feeding means or a sheet feed table;

50 Fig. 2 represents a cross section taken in the plane of the line II-II of Fig. 1, looking in the directions of the arrows;

Fig. 3 represents a detail side elevation, partly in section, with the parts in the positions they 55 assume as the sheet feed carrier grippers are transferring the sheet to the impression cylinder grippers at substantially the same surface speed of the impression cylinder;

Fig. 4 represents a detail cross a; stion, taken in the plane of the line IV-IV of Fig. 2, looking in the direction of the arrows; and

Fig. 5 represents, on an enlarged scale, a diagrammatic view illustrating the relative positions of the sheet feed carrier and the means for varying its surface speeds during one rotation there- 10 of with respect to the constant surface speed of the impression cylinder.

The impression cylinder I, form cylinder 2, and delivery cylinder 3 are all driven at a constant surface speed through the gears 4, 5, and i5 6. Two sets of sheet grippers I (one only of which sets is shown herein) are provided on the impression cylinder I.

The source of sheet supply may be a sheet feed table 8, on which table the sheets are stopped 20 and registered in any well known or approved manner, not shown herein. i

A variable speed sheet feed rotary carrier 9 is interposed between the sheet feed table 8 and the impression cylinder i, the shaft U of which 25 sheet feed carrier is suitably mounted in the side frame H and projects a distance beyond the same. This sheet feed carrier 9 is shown herein as one-half the diameter of the impression cylinder I and it rotates twice for each rotation of the impression cylinder. A set of sheet grippers i2 is provided on the sheet feed carrier 9.

The sheet feed carrier 9 is operated to cause, in one revolution of the carrier, the sheet grippers l2 to take a sheet from the sheet feed table 8 at a speed slower than the surface speed of the impression cylinder, to then be accelerated to a. surface speed considerably beyond that of the impression cylinder, and to thereafter be slowed down to a surface speed substantially that of the impression cylinder, to permit the sheet feed carrier grippers l2 to transfer the sheet to one of the sets of impression cylinder grippers 1. The means for accomplishing the above result is constructed, arranged and operated as follows:

The hub l3 of the sheet feed carrier gear I4 is loosely mounted on the outer end of the sheet feed carrier shaft l0 and it is driven at a constant speed by the impression cylinder gear 4, through the gear l4, two rotations for each rotation of the impression cylinder gear. A backlash preventing gear I5 may be provided for the sheet feed carrier gear I4, if so desired.

A box cam I6 is secured to the outer face of the side frame Ii around'the sheet feed carrier shaft III, which cam has a continuous groove ll of the desired shape.

A gear segment I8 is fixedly mounted on the sheet feed carrier shaft ll between the hub l3 of the loosely mounted gear l4 and the box cam IS, the teeth of whichsegment l8 mesh with the teeth of'a gear segment l9 loosely mounted on a stud shaft 20 projecting inwardly from the sheet feed carrier gear hub l3. 7 A backlash preventing gear segment 2| may be provided for the gear segment I 9, if so desired. This gear segment I9 is provided with a cam lever 22 carrying a stud and roller 23 which travels around the sheet feed carrier shaft l0 within the cam groove ll of the box cam "5 as the loosely mounted sheet feed carrier gear i4 is rotated by the constant speed impression cylinder gear 4.

A light friction spring brake surrounds the sheet feed carrier shaft In between the inner face of the side frame It and the sheet feed carrier 9, which brake acts as a light drag on said shaft to prevent the overrunning of the sheet feed carrier when it is being slowed down. This brake is herein shown as comprising two semicircular brake arms 24, 25, pivoted at 26 to a bracket support 21, carried by the said frame II. The free ends of these arms are yieldingly urged toward each other by providing a pin 28 projecting from one arm through the other arm, and

a coil spring 23 located between said other arm and a lock nut 30 on said pin.

In operation: It will be seen that while the impression cylinder gear 4 and the loosely mounted sheet feed carrier gear l4 both travel at a uniform constant speed, the impression cylinder gear travels one rotation to two rotations of the feed carrier gear and that the shape of the cam groove ll is such that it will swing the stud and roller 23 of the cam lever 22 outwardly and inwardly to a greater or lesser extent during the rotation of the feed carrier gear l4 and thus rock the gear segment l9 around the gear segment l8 to delay and accelerate the rotation of the sheet feed carrier 9 through its shaft ID on which the gear segment I 8 is fixedly mounted.

These parts are so proportioned and arranged as will be seen from the diagram, Fig. 5, that the surface speed of the feed cylinder during one rotation thereof will be as follows:

Presupposing the parts to be in the positions shown in Figs. 1 and 5 and the grippers l2 of the sheet feed carrier have taken a stopped and registered sheet from the sheet feed table. The continued movement of the impression and feed carrier' gears 4 and I4 will, because of the effect of the box cam "5 on the gear segment l9 through the stud and roller 23 on the cam lever 22, rock the gear segment I9 in a direction to rapidly accelerate the surface speed of the sheet feed carrier 9 and thereby raise its surface speed considerably beyond that of the impression cylinder I. When the sheet grippers I2 have moved to a position about two-thirds of the distance towardthe transfer point, the sheet feed carrier will be slowed down by the-cam l6 so that, as the transfer point is reached, the sheet feed carrier grippers will be traveling at substantially the constant high surface speed of the impression cylinder and the sheet may be transferred from the grippers l2 to the grippers I. These substantially coincident surface speeds of the sheet feed carried and the impression cylinder are maintained while the grippers l2 travel for a considerable distance toward their sheet taking point. However, a short time before the grippers I2 reach their sheet taking point the cam i8 causes the sheet feed carrier to gradually slow down until the carrier reaches its lowest surface speed as the grippers l2 reach their sheet taking position. This completes the cycle of operations during one rotation of the sheet feed carrier, and it will be understood that the operation is repeated'with each succeeding sheet.

The above cycle of operations is graphically illustrated in the diagram, Fig. 5. The dot and dash line (1 represents the sheet take ofi point. The dot and dash line b represents the point where the slowing down of the feed carrier is started. The dot and dash line (2 represents the sheet transfer point. The dot and dash line it represents the point where the slowing down of the sheet feed carrier is started to its lowest surface speed at the sheet take 011 point. The speeding up of the surface speed of the sheet feed carrier to a point considerably greater than that of the impression cylinder occurs substantially between the lines a and b. The primary slowing down of the surface speed of the sheet feed carrier occurs substantially between the lines b and c. The constant speed occurs substantially between the lines 0 and d. Thefinal slowing down of the surface speed of the sheet feed cylinder occurs substantially between the lines d and a.

The outwardly directed equally spaced lines denoted by V represent the constant surface movement of the feed carrier gear Id. The inwardly directed unequally spaced lines W illustrate the varying surface speed of the sheet feed carrier 9. various positions of the cam lever stud and roller 23. The lines Y represent .the angular movement of the gear segment l9. The large circles Z, Z illustrate the positions of the cam lever pivot shaft 20 at the sheet taking and sheet transfer points respectively.

The rapid acceleration of the feed carrier from its sheet taking point toward its sheet transfer point to a speed considerably higher than that of the impression cylinder accomplishes two results. First, it allows the feed carrier grippers to catch up to the impression cylinder grippers in their proper cycle, and, second, it allows additional sheet length to be handled which could not be handled by a feed carrier of the same size traveling at a constant surface speed or at a variable surface speed at all times below the surface speed of the impression cylinder.

From the above description it will be seen that I have provided a simple and effective means for taking the sheets at a low surface speed, accelerating the sheets to a very high surface speed to take them rapidly'away from the sheet feed table, to then slow down the sheets to substantially the surface speed of the impression cylinder, and to finally again slow down the sheet feed carrier to permit it to take the next succeeding sheet at about the lowest surface speed of the said'carrier.

It is evident that various changes may be resorted to in the construction, form and arrangement of the several parts without departing from the spirit and scope of my invention, and hence I do not intend to be limited to the particular embodiment herein shown and described, but

What I claim is: p

1. In a sheet feed rotary printing press, a sheet feed carrier rotating continuously in one direction atvariable speeds, and means for causing it to slow down to take a sheet, to-speed up and to then slow down to transfer the sheet. 1

2. In a sheet feed rotary printing press, a sheet The small circles x illustrate the auaus feed carrier rotating continuously in one direction at variable speeds, and means for causing it to slow down to take a sheet, to speed up and to then slow down to transfer the sheet, said means including a feed carrier shaft, a constant speed feed carrier gear loosely mounted thereon, two intermeshing gear segments, one fixedly mounted on the feed carrier shaft and the other loosely mounted on the feed carrier gear and a stationary cam for rocking the feed carrier gear segment.

3. In a sheet feed rotary printing press, a sheet feed carrier rotating continuously in one direction at variable speeds, and means for causing it to slow down to take a sheet, to speed up and to then slow down to transfer the sheet, said means including a feed carrier shaft, a constant speed feed carrier gear loosely mounted thereon, two intermeshing gear segments, one fixedly mounted on the feed carrier shaft and the other loosely mounted on the feed carrier gear, a stationary cam and a cam lever carried by the feed carrier gear segment and operated by said cam.

4. In a sheet feed rotary printing press, a sheet feed carrier rotating continuously in one direction at variable speeds, and means for causing it to slow down to take a sheet, to speed up and to then slow down to transfer the sheet and a friction brake for preventing the overrunning of the sheet feed carrier.

5. In a sheet feed rotary printing press, a sheet feed carrier rotating continuously in one direction at variable speeds, and means for causing it to slow down to take a sheet, to speed up and to then slow down to transfer the sheet, said means including a feed carrier shaft, a constant speed feed carrier gear loosely mounted thereon, two intermeshing gear segments, one fixedly mounted on the feed carrier shaft and the other loosely mounted on the feed carrier gear and a stationary cam for rocking the feed carrier gear segment and a-friction brake acting on the said feed carrier shaft for preventing the overrunning of the car- 6. In a sheet feed rotary printing press, a variable speed sheet feed rotary carrier, and means for causing it to slow down to take a sheet, to speed up and to then slow down to transfer the sheet, said means including a feed carrier shaft, a constant speed feed carrier gear loosely mounted thereon two intermeshing gear segments, one fixedly mounted on, the feed carrier shaft and the other loosely mounted on the feed carrier gear and a stationary cam for rocking the feed carrier gear segment and a backlash preventer for the feed carrier gear.

7; In a sheet feed rotary printing press, a variable speed sheet feed rotary carrier, and means for causing it to slow down to take a sheet, to speed up and to then slow down to transfer the sheet, said means including a feed carrier shaft,

a constant speed feed carrier gear loosely mounted thereon, two intermeshing gear segments, one fixedly mounted on the feed carrier shaft and the other loosely mounted on the feed carrier gear and a stationary cam for rocking the feed carrier gear segment and a backlash preventer for the gear segments.

8. In a sheet feed rotary printing press, a variable speed sheet feed rotary carrier, and means for causing it to slow down to take a sheet, to speed up and to then slow down to transfer the sheet, said means including a feed carrier shaft, a constant speed feed carrier gear loosely mounted thereon, two intermeshing gear segments, one fixedly mounted on the feed carrier shaft and the other loosely mounted on the feed carrier gear and a stationary cam for rocking the feed carrier gear segment, a friction brake acting on the said feed carrier shaft for preventing the overrunning of the carrier and backlash preventers for the feed carrier gear and the gear segments.

9. In a sheet feed rotary printing press, a sheet feed carrier rotating continuously in one direction at variable speeds and arranged to take a sheet at one point in its rotation and to transfer the sheet at another point in its rotation, and means for causing the sheet feed carrier to slow down to a low surface speed at the sheet taking point, to accelerate a much higher speed after leaving the sheet taking point and to slow down to a lower surface speed at the sheet transfer point.

10. In a sheet feed rotary printing press, a sheet-supply, a constant speed impression cylinder, a sheet feed carrier rotating continuously in one direction at variable speeds, and means for causing it to slow down to take a sheet from the sheet supply, to speed up to a higher surface speed than that of 'the impression cylinder and to slow down to transfer the sheet at approximately the surface speed of the impression cylinder.

11. In a sheet feed rotary printing press, a frame, a sheet feed carrier rotating continuously in one direction and having its shaft mounted in the frame, a gear loosely mounted on the shaft outside of the frame, an impression cylinder having a gear meshing with the feed carrier gear, and means for varying the surface speed of the feed carrier comprising a stationary cam carried by the frame and intermeshing gear segments located between the cam and feed carrier gear, one segment being carried by the feed carrier gear and the other segment fixedly mounted onsaid shaft, said feed carrier gear'segment being provided with a stud and roller engaged by said cam.

12. In a sheet feed rotary printing press, a frame, a sheet feed carrier rotating continuously in one direction and having its shaft mounted in the frame, a gear loosely mounted on the shaft outside of the frame, an impression cylinder having a gear meshing with the feed carrier gear, and means for varying the surface speed of the feed carrier comprising a stationary box cam carried by the frame and surrounding said shaft and intermeshing gear segments located between the cam and feed carrier gear, one segment being carried by the feed carrier gear and the other segment fixedly mounted on said shaft, said feed carrier gear segment being provided with a lever having a stud and roller traveling in the box cam ITOOVO.

WALTER G. HACKBARTH. 

